package theme_files

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

// Store owns writes under a single configured storage directory. Replacing an
// archive uses a temporary file so readers never receive partially written ZIPs.
type Store struct{ root string }

func NewStore(root string) (*Store, error) {
	absolute, err := filepath.Abs(root)
	if err != nil {
		return nil, err
	}
	if err := os.MkdirAll(filepath.Join(absolute, "previews"), 0755); err != nil {
		return nil, err
	}
	return &Store{root: absolute}, nil
}
func (s *Store) Root() string { return s.root }
func (s *Store) checked(path string) (string, error) {
	absolute, err := filepath.Abs(path)
	if err != nil {
		return "", err
	}
	relative, err := filepath.Rel(s.root, absolute)
	if err != nil || relative == "." || relative == ".." || strings.HasPrefix(relative, ".."+string(filepath.Separator)) || filepath.IsAbs(relative) {
		return "", fmt.Errorf("file path is outside theme storage")
	}
	return absolute, nil
}
func (s *Store) WriteFile(path string, data []byte, mode os.FileMode) error {
	target, err := s.checked(path)
	if err != nil {
		return err
	}
	file, err := os.CreateTemp(filepath.Dir(target), ".upload-*")
	if err != nil {
		return err
	}
	temp := file.Name()
	defer os.Remove(temp)
	if _, err := file.Write(data); err != nil {
		file.Close()
		return err
	}
	if err := file.Chmod(mode); err != nil {
		file.Close()
		return err
	}
	if err := file.Close(); err != nil {
		return err
	}
	return os.Rename(temp, target)
}
func (s *Store) Remove(path string) error {
	target, err := s.checked(path)
	if err != nil {
		return err
	}
	if err := os.Remove(target); err != nil && !os.IsNotExist(err) {
		return err
	}
	return nil
}